Two DNA polymorphisms in the lipoprotein lipase gene and their associations with factors related to cardiovascular disease

Associations of the LPL S447X and Hind III Polymorphism with Type 2 Diabetes Mellitus Risk: A Meta-Analysis

The present study was aimed to evaluate the association of lipoprotein lipase (LPL) gene (S447X and Hind III) polymorphisms and T2DM. Relevant studies were identified through systematic search PubMed, Cochrane Library, Embase, Wanfang, CNKI databases. A total of 22 studies (8 studies for LPL S447X and 14 studies for Hind III) were included. The results showed that the LPL S447X polymorphism was associated with the low risk of T2DM under dominant and allelic genetic models. Subgroup analysis by ethnicity showed that the LPL S447X polymorphism was associated with a decreased risk of T2DM in the Asian population (under dominant, heterozygous and allelic genetic models). In addition, we found that X allele carriers of S447X polymorphism is associated with low levels of TC, TG, and LDL. In subgroup analysis, Hind III polymorphism was associated with low risk of T2DM in Asian populations (under dominant, heterozygote, allele genetic models). Moreover, the carriers of H allele of Hind III have lower levels of TG, and higher levels of HDL-C. This meta-analysis demonstrated that 447X carriers and H allele in LPL gene associated with low risk of T2DM, which may due to in part to the change of serum level of TC, TG, LDL, and HDL.

Understanding the growing epidemic of type 2 diabetes in the Hispanic population living in the United States

The prevalence and incidence of type 2 diabetes (T2D) among the Hispanic population in the United States are higher than the national average. This is partly due to sociocultural factors, such as lower income and decreased access to education and health care, as well as a genetic susceptibility to obesity and higher insulin resistance. This review focuses on understanding the Hispanic population living in the United States from a multidisciplinary approach and underlines the importance of cultural, social, and biological factors in determining the increased risk of T2D in this population. An overview of the acute and chronic complications of T2D upon this population is included, which is of paramount importance to understand the toll that diabetes has upon this population, the health system, and society as a whole. Specific interventions directed to the Hispanic populations are needed to prevent and alleviate some of the burdens of T2D. Different prevention strategies based on medications, lifestyle modifications, and educational programmes are discussed herein. Diabetes self-management education (DSME) is a critical element of care of all people with diabetes and is considered necessary to improve patient outcomes. To be more effective, programmes should take into consideration cultural factors that influence the development and progression of diabetes. These interventions aim to enhance long-term effects by reducing the incidence, morbidity, and mortality of T2D in the Hispanic population of the United States.

Common variants in the genes of triglyceride and HDL-C metabolism lack association with coronary artery disease in the Pakistani subjects

Background

Serum Triglyceride (TG) and High Density Lipoprotein (HDL-C) levels are modifiable coronary artery disease (CAD) risk factors. Polymorphisms in the genes regulating TG and HDL-C levels contribute to the development of CAD. The objective of the current study was to investigate the effect of four such single nucleotide polymorphism (SNPs) in the genes for Lipoprotein Lipase (LPL) (rs328, rs1801177), Apolipoprotein A5 (APOA5) (rs66279) and Cholesteryl ester transfer protein (CETP) (rs708272) on HDL-C and TG levels and to examine the association of these SNPs with CAD risk.

Methods

A total of 640 subjects (415 cases, 225 controls) were enrolled in the study. The SNPs were genotyped by KASPar allelic discrimination technique. Serum HDL-C and TG were determined by spectrophotometric methods.

Results

The population under study was in Hardy Weinberg equilibrium and minor allele of SNP rs1801177 was completely absent in the studied subjects. The SNPs were association with TG and HDL-C levels was checked through regression analysis. For rs328, the effect size of each risk allele on TG and HDL-C (mmol/l) was 0.16(0.08) and −0.11(0.05) respectively. Similarly, the effect size of rs662799 for TG and HDL-C was 0.12(0.06) and −0.13(0.0.3) and that of rs708272 was 0.08(0.04) and 0.1(0.03) respectively. The risk allele frequencies of the SNPs were higher in cases than controls, but the difference was not significant (p > 0.05) and SNPs were not associated with CAD risk (p > 0.05). The combined gene score of four SNPs significantly raised TG and lowered HDL-C but did not increase CAD risk.

Conclusion

The studied SNPs were associated with TG and HDL-C levels, but not with CAD in Pakistani population under study.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-017-0419-4) contains supplementary material, which is available to authorized users.

Resequencing of LPL in African Blacks and associations with lipoprotein-lipid levels

Genome-wide association studies have identified several loci associated with plasma lipid levels but those common variants together account only for a small proportion of the genetic variance of lipid traits. It has been hypothesized that the remaining heritability may partly be explained by rare variants with strong effect sizes. Here, we have comprehensively investigated the associations of both common and uncommon/rare variants in the lipoprotein lipase (LPL) gene in relation to plasma lipoprotein-lipid levels in African Blacks (ABs). For variant discovery purposes, the entire LPL gene and flanking regions were resequenced in 95 ABs with extreme high-density lipoprotein cholesterol (HDL-C) levels. A total of 308 variants were identified, of which 64 were novel. Selected common tagSNPs and uncommon/rare variants were genotyped in the entire sample (n=788), and 126 QC-passed variants were evaluated for their associations with lipoprotein-lipid levels by using single-site, haplotype and rare variant (SKAT-O) association analyses. We found eight not highly correlated (r(2)<0.40) signals (rs1801177:G>A, rs8176337:G>C, rs74304285:G>A, rs252:delA, rs316:C>A, rs329:A>G, rs12679834:T>C, and rs4921684:C>T) nominally (P<0.05) associated with lipid traits (HDL-C, LDL-C, ApoA1 or ApoB levels) in our sample. The most significant SNP, rs252:delA, represented a novel association observed with LDL-C (P=0.002) and ApoB (P=0.012). For TG and LDL-C, the haplotype analysis was more informative than the single-site analysis. The SKAT-O analysis revealed that the bin (group) containing 22 rare variants with MAF≤0.01 exhibited nominal association with TG (P=0.039) and LDL-C (P=0.027). Our study indicates that both common and uncommon/rare LPL variants/haplotypes may affect plasma lipoprotein-lipid levels in general African population.

Lipoprotein lipase and PPAR alpha gene polymorphisms, increased very-low-density lipoprotein levels, and decreased high-density lipoprotein levels as risk markers for the development of visceral leishmaniasis by Leishmania infantum

In visceral leishmaniasis (VL) endemic areas, a minority of infected individuals progress to disease since most of them develop protective immunity. Therefore, we investigated the risk markers of VL within nonimmune sector. Analyzing infected symptomatic and, asymptomatic, and noninfected individuals, VL patients presented with reduced high-density lipoprotein cholesterol (HDL-C), elevated triacylglycerol (TAG), and elevated very-low-density lipoprotein cholesterol (VLDL-C) levels. A polymorphism analysis of the lipoprotein lipase (LPL) gene using HindIII restriction digestion (N = 156 samples) (H+ = the presence and H− = the absence of mutation) revealed an increased adjusted odds ratio (OR) of VL versus noninfected individuals when the H+/H+ was compared with the H−/H− genotype (OR = 21.3; 95% CI = 2.32–3335.3; P = 0.003). The H+/H+ genotype and the H+ allele were associated with elevated VLDL-C and TAG levels (P < 0.05) and reduced HDL-C levels (P < 0.05). An analysis of the L162V polymorphism in the peroxisome proliferator-activated receptor alpha (PPARα) gene (n = 248) revealed an increased adjusted OR when the Leu/Val was compared with the Leu/Leu genotype (OR = 8.77; 95% CI = 1.41–78.70; P = 0.014). High TAG (P = 0.021) and VLDL-C (P = 0.023) levels were associated with susceptibility to VL, whereas low HDL (P = 0.006) levels with resistance to infection. The mutated LPL and the PPARα Leu/Val genotypes may be considered risk markers for the development of VL.

The gene-diet interaction, LPL PvuII and HindIII and carbohydrate, on the criteria of metabolic syndrome: KMSRI-Seoul Study

OBJECTIVE

The objective of this study was to investigate the effects of the interaction between lipoprotein lipase (LPL) PvuII and HindIII haplotypes and carbohydrate intakes on the components of metabolic syndrome (MetSyn) in Koreans.

METHODS

LPL PvuII and HindIII genotype, LPL mass, triglyceride, high-density lipoprotein cholesterol, blood pressure (BP), waist circumference (WC), insulin, and Homeostasis Model of Assessment - Insulin Resistance were determined using a cross-sectional design in 269 controls and 280 MetSyn patients.

RESULTS

LPL mass was significantly lower in patients with PvuII and HindIII mutant alleles (P2 and H2) and decreased as the number of MetSyn components increased in all PvuII and HindIII haplotypes. Both LPL mass-adjusted WC and systolic BP (SBP) were positively associated with a ratio of percent energy from carbohydrate to percent energy from fat in individuals with P2H2 haplotype. After adjustment for age, sex, and LPL mass, the odds ratio (OR) for excessive WC was higher in carriers of P2H2 in the highest carbohydrate intake tertile compared with carriers of P1H1 in the lowest carbohydrate intake tertile (OR, 6.94; 95% confidence interval [CI], 1.39-34.62). Moreover, the OR for high SBP were higher in carriers of P1H2/P2H1 in the highest carbohydrate intake tertile (OR, 7.84; 95% CI, 1.79-34.46) and in carriers of P2H2 in the highest carbohydrate intake tertile (OR, 4.24; 95% CI, 1.16-15.48) than P1H1 carriers.

CONCLUSION

This study suggests that P2H2 carriers in the highest carbohydrate intake tertile may be at risk for MetSyn because they had increased odds of excessive WC and high SBP.

Lipoprotein lipase gene HindIII polymorphism and risk of myocardial infarction in South Indian population

INTRODUCTION

Studies have reported an association between lipoprotein lipase (LPL) gene and myocardial infarction in some populations. Therefore, the present study aimed to investigate the association of the HindIII polymorphism of the (LPL) gene with myocardial infarction and to explore its potential role in susceptibility in a South Indian population.

SUBJECTS AND METHODS

We included a total of 412 subjects (202 myocardial infarction patients and 210 age- and sex-matched controls). Demographic and clinical characteristics were collected. Lipid profiles were estimated. DNA was isolated and the LPL gene HindIII polymorphism was determined by polymerase chain reaction.

RESULTS

Comparison of the lipid profiles between patients and controls showed that patients had statistically high significant values (p = 0.0001). The H(+) H(+) genotype of the LPL gene is associated with myocardial infarction. H(+) H(+) vs. H(-) H(-) was χ2 = 19.4, OR 3.1, CI 95% 1.8-5.2, p < 0.0001.

CONCLUSION

Our study strongly suggests that the LPL gene HindIII Hþ Hþ genotype is an independent risk factor for first MI.

Lipoprotein lipase gene sequencing and plasma lipid profile

Lipoprotein lipase (LPL) plays a crucial role in lipid metabolism by hydrolyzing triglyceride (TG)-rich particles and affecting HDL cholesterol (HDL-C) levels. In this study, the entire LPL gene plus flanking regions were resequenced in individuals with extreme HDL-C/TG levels (n = 95), selected from a population-based sample of 623 US non-Hispanic White (NHW) individuals. A total of 176 sequencing variants were identified, including 28 novel variants. A subset of 64 variants [common tag single nucleotide polymorphisms (tagSNP) and selected rare variants] were genotyped in the total sample, followed by association analyses with major lipid traits. A gene-based association test including all genotyped variants revealed significant association with HDL-C (P = 0.024) and TG (P = 0.006). Our single-site analysis revealed seven independent signals (P < 0.05; r² < 0.40) with either HDL-C or TG. The most significant association was for the SNP rs295 exerting opposite effects on TG and HDL-C levels with P values of 7.5.10⁻⁴ and 0.002, respectively. Our work highlights some common variants and haplotypes in LPL with significant associations with lipid traits; however, the analysis of rare variants using burden tests and SKAT-O method revealed negligible effects on lipid traits. Comprehensive resequencing of LPL in larger samples is warranted to further test the role of rare variants in affecting plasma lipid levels.

Associations of three lipoprotein lipase gene polymorphisms, lipid profiles and coronary artery disease

Lipoprotein lipase (LPL) plays a central role in lipoprotein metabolism by hydrolyzing the core triglycerides (TGs) of circulating chylomicrons and very-low-density lipoprotein (VLDL). The effects of LPL polymorphisms on lipid levels and coronary artery disease (CAD) have been inconsistent among studies and populations. To assess the lipid profiles and distributions of three LPL gene polymorphisms in Saudi patients with CAD, the HindIII, PvuII and Ser447Ter polymorphisms in the LPL gene were analyzed in 226 patients with CAD and 110 controls. Polymerase chain reaction-restriction fragment length polymorphism was used to detect LPL gene polymorphisms. The plasma lipid profiles of the patients were determined using standard enzymatic methods. Patients in the CAD group had significantly higher triglyceride (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels than controls irrespective of the HindIII, PvuII or Ser447Ter genotype. Compared to the findings in controls, the HindIII TT, PvuII TC and Ser447Ter CC genotypes were associated with significantly reduced high-density lipoprotein cholesterol (HDL-C) levels in patients with CAD (P<0.0001). In summary, there are associations between LPL gene variants and high plasma TG, TC and LDL-C levels as well as low HDL-C levels.

DNA polymorphisms of the lipoprotein lipase gene and their association with coronary artery disease in the Saudi population

Coronary heart disease (CHD) is a major health problem and a major cause of death in most countries. Evidence has been presented that gene polymorphisms (HindIII, PvuII and Ser447Ter) of lipoprotein lipase (LPL) are risk factors of coronary artery disease (CAD).

AIM

Our objective of the present investigation was to determine whether 3 LPL polymorphisms (LPL-HindIII, LPL-PvuII and LPL-Ser447Ter) can be considered as independent risk factors for CAD in the Saudi population.

METHODS

We recruited 120 CAD subjects, confirmed angiographically with identical ethnic backgrounds and 65 control subjects. Polymerase chain reaction-restriction fragment length polymorphisms (RFLP) technique was used to detect the polymorphisms of the LPL gene.

RESULTS AND CONCLUSION

For the HindIII genotype, within the CAD group, the frequencies of the H(+)H(+) were found in 50.8%, whereas 44.2% carried the H(-)H(+) genotype, and 5% carried the H(-)H(-) genotype. Within the control group, the H(+)H(+) genotype was found in 44.6%, whereas 35.4% carried the H(-)H(+) genotype, 20% carried the H(-)H(-) genotype. The odds ratio (OR) of HindIII genotype H(+)H(+)vs. H(-)H(-) genotype at 95% Confidence Interval (CI) were 4.6 (1.57-13.2) and p < 0.005, hence showing no significant association with CAD. For the PvuII genotype, within the CAD group the frequencies of the P(+)P(+) found in 41.7% whereas 43.3.2% carried the P(-)P(+) genotype, and 15% carried the P(-)P(-) genotype. Within the control group the P(+)P(+) was found in 38.5%, 43.0% carried the P(-)P(+) genotype, and 18.5% carried the P(-)P(-) genotype. The OR of PvuII genotype P(+)P(+)vs. P(-)P(-) genotypes (95% CI) is 1.33 and p = 0.52; hence, it was also insignificant to show association with the disease. For the Ser447Ter genotype, within the CAD group, the frequencies of the C/C found in 83.3%, whereas 16.7% carried the C/G genotype. Within the control group, the C/C was found in 87.7% and 12.3% carried the C/G genotype. We did not get any GG genotypes in control as well as patients for this gene. It can be concluded that C allele of gene masks the presence of G allele in the Saudi population. The OR of CG + GG vs. CC (95% CI) is 1.43 from 0.59 to 3.44 which is insignificant. Hence this gene also has no significant association with CAD in the Saudi population.

The association of lipoprotein lipase PvuII polymorphism and niacin intake in the prevalence of metabolic syndrome: a KMSRI-Seoul study

Lipoprotein lipase (LPL) polymorphism correlated with LPL activity is associated with plasma lipid and lipoprotein levels. We aimed to investigate the frequency of LPL PvuII polymorphism and effects of LPL PvuII polymorphism and niacin intake on the prevalence of metabolic syndrome (MetSyn) in Koreans. Lifestyle questionnaires, anthropometry, and dietary records were completed, and LPL PvuII polymorphism, LPL mass, and lipid profiles were determined in 548 Koreans (MetSyn: 278, Non-MetSyn: 270). The MetSyn group showed a significantly lower frequency of P1P1 (wild type) and a higher frequency of P1P2 (hetero type) than the non-MetSyn group. The P2P2 (mutant type) group significantly showed lower levels of HDLc and LPL mass and a higher level of TG than the P1P1 group. As niacin intake increased, LPL mass decreased in the P2P2 group (r (2) = 0.07). In particular, the lowest niacin intake group (≤14.82 mg/day) increased more than 3 times with regard to a higher risk of MetSyn than the others in the P2P2 mutant groups. However, the MetSyn risk declined 74% at the optimal levels of niacin intake (14.83-17.80 mg/day) in the P2P2 group compared to those of the P1 allele group. The findings indicate that optimal levels of niacin intake effectively decreased Korean MetSyn prevalence in the P2P2 mutant group.

Genetic-epidemiological evidence on genes associated with HDL cholesterol levels: a systematic in-depth review

High-density lipoprotein (HDL) particles exhibit multiple antiatherogenic effects. They are key players in the reverse cholesterol transport which shuttles cholesterol from peripheral cells (e.g. macrophages) to the liver or other tissues. This complex process is thought to represent the basis for the antiatherogenic properties of HDL particles. The amount of cholesterol transported in HDL particles is measured as HDL cholesterol (HDLC) and is inversely correlated with the risk for coronary artery disease: an increase of 1mg/dL of HDLC levels is associated with a 2% and 3% decrease of the risk for coronary artery disease in men and women, respectively. Genetically determined conditions with high HDLC levels (e.g. familial hyperalphalipoproteinemia) often coexist with longevity, and higher HDLC levels were found among healthy elderly individuals. HDLC levels are under considerable genetic control with heritability estimates of up to 80%. The identification and characterization of genetic variants associated with HDLC concentrations can provide new insights into the background of longevity. This review provides an extended overview on the current genetic-epidemiological evidence from association studies on genes involved in HDLC metabolism. It provides a path through the jungle of association studies which are sometimes confusing due to the varying and sometimes erroneous names of genetic variants, positions and directions of associations. Furthermore, it reviews the recent findings from genome-wide association studies which have identified new genes influencing HDLC levels. The yet identified genes together explain only a small amount of less than 10% of the HDLC variance, which leaves an enormous room for further yet to be identified genetic variants. This might be accomplished by large population-based genome-wide meta-analyses and by deep-sequencing approaches on the identified genes. The resulting findings will probably result in a re-drawing and extension of the involved metabolic pathways of HDLC metabolism.

Lipoprotein lipase PvuII polymorphism is associated with variations in serum lipid levels in non-diabetic pregnant women

The aim of the present study was to determine if there is an association between the single nucleotide polymorphisms (SNPs) of the lipoprotein lipase (LPL) and apolipoprotein E (apo E) genes and the serum lipid profile in pregnancy and puerperium. Non-diabetic women of European descent in the third semester of pregnancy (N = 120) were selected. Those with diseases or other condition that could modify their lipid profile were excluded from the study (N = 32). Serum lipids were measured by routine laboratory procedures and genomic DNA was extracted by a salting out method. LPL (PvuII and HindIII) and apo E (HhaI) SNPs were detected by the polymerase chain reaction and restriction fragment length polymorphism. Categorical and continuous variables were compared by the chi-square test and Student t-test or ANOVA, respectively. Women carrying the LPL P1P1 genotype had higher serum LDL cholesterol (N = 21; 155 +/- 45 mg/dL) than women carrying the P1P2/P2P2 genotypes (N = 67; 133 +/- 45 mg/dL; P = 0.032). During the puerperium period, serum levels of triglycerides and VLDL cholesterol were significantly reduced in women carrying the P1P1 (73%, P = 0.006) and P1P2 (51%, P = 0.002) genotypes but not in women carrying the P2P2 genotype (23%, P > 0.05). On the other hand, serum concentrations of lipids did not differ between the LPL HindIII and apo E genotypes during pregnancy and after delivery. We conclude that LPL PvuII SNP is associated with variations in serum lipids during pregnancy and the puerperal period in non-diabetic women.

Inconsistencies in the genetic prediction of HDL cholesterol versus atherosclerosis

PURPOSE OF REVIEW

High-density lipoprotein (HDL) is generally perceived as having a protective role with respect to cardiovascular disease. The metabolism of HDL is mediated through a complex network of apoproteins, enzymes and transfer proteins. Genetic variants within this network can increase plasma HDL, but not with uniformly beneficial clinical outcomes. The purpose of this review is to explore and propose mechanisms for these discrepant observations.

RECENT FINDINGS

Recent developments in this area include new observations of genetic variants that paradoxically increase both HDL and cardiovascular risk. Also discussed are newly observed, function-altering modifications of the HDL particle. Proposed explanations include the segregation of the genetic variants associated with the respective endpoints of plasma HDL and cardiovascular risk. Functionally impaired but quantitatively robust plasma HDL and the emerging understanding of proinflammatory HDL also may contribute to our understanding of discordant observations.

SUMMARY

Enhanced understanding of these relationships may allow a more accurate assessment of clinical risk based on plasma HDL and help explain why HDL may, in some circumstances, be an inappropriate therapeutic target.

Lipoprotein lipase HindIII polymorphism influences HDL-cholesterol levels in statin-treated patients with coronary artery disease

BACKGROUND

HDL-cholesterol (HDL-C) is a recognized athero-protective factor and low levels of HDL-C occur frequently in patients with coronary artery disease. Regulation of HDL-C level most probably results from the interaction of genes involved in lipoprotein metabolism and also from non-genetic factors. We studied associations and interactions among HindIII polymorphisms of the lipoprotein lipase gene LPL and selected non-genetic factors with respect to HDL-C levels in patients with coronary artery disease.

PATIENTS AND METHODS

288 Slovak patients (35% women) with documented coronary artery disease, age (mean +/- SEM) 60 +/- 1 years and BMI 29 +/- 0.3 kg/m(2), were examined and genotyped for LPL HindIII (rs320) using a PCR/RFLP method. HDL-C levels were determined in a direct enzymatic assay.

RESULTS

In the sample overall there were no significant differences across the LPL genotypes in adjusted HDL-C levels or in other lipids, although a trend toward higher HDL-C and lower triglycerides in H-H- homozygotes was observed. Multiple linear regression identified a significant interaction between LPL HindIII and statin treatment, which together with sex and diabetes explained 12.1% of HDL-C variance. Accordingly, in statin-treated patients we observed significant stepwise increments of the HDL-C level related to the increasing number of H- alleles (P = 0.04 for linear trend), whereas no such association was observed in patients without hypolipidemic treatment. H-H- homozygotes had a 16% (0.19 mmol/l) higher level of HDL-C than the H+H+ homozygotes (P = 0.06).

CONCLUSION

HDL-C may be influenced by an interaction between statin treatment and LPL HindIII genotype. However, the effect of this interaction appears to be small when compared with the effect of non-genetic factors. This finding requires replication in a pharmacogenetic study.

Association of lipase lipoprotein polymorphisms with myocardial infarction and lipid levels

BACKGROUND

Lipoprotein lipase has an important role in lipid metabolism. Elevated levels of very-low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) are associated with increased risk of coronary artery disease and low levels of high-density lipoprotein (HDL) are potentially atherogenic. The HindIII and S447X polymorphisms of the lipoprotein lipase (LPL) gene are associated with cardiovascular disease in some populations.

METHODS

LPL HindIII and S447X polymorphisms were analyzed in 343 individuals of 66-97 years of age from a cohort of a Brazilian elderly longitudinal study. Allele frequencies, genotype distribution and allele association with major morbidities and with serum lipid, urea, creatinine and albumin levels were also investigated. The whole sample was genotyped by PCR-restriction fragment length polymorphism (RFLP). Descriptive statistics, logistic regression analysis and t-test were used.

RESULTS

Allele frequencies were H(+)=0.652 and H(-)=0.348 for LPL HindIII and S=0.824 and X=0.176 for LPL S447X polymorphism. Both polymorphisms have frequencies similar to those in some European populations. LPL HindIII polymorphism showed significant association of the H(+) allele with myocardial infarction. The H(-) allele showed a tendency to associate with higher HDL levels. The LPL S447X S allele was associated with higher triglyceride levels.

CONCLUSIONS

These findings may help to identify risk factors for subjects and families and clarify the physiopathological role of these polymorphisms in age-related diseases.

Impact of lipoprotein lipase gene polymorphisms on ulcerative colitis

AIM: To examine the influence of lipoprotein lipase (LPL) gene polymorphism in ulcerative colitis (UC) patients.

METHODS: Peripheral blood was obtained from 131 patients with UC and 106 healthy controls for DNA extraction. We determined LPL gene polymorphisms affecting the enzyme at Ser447stop, as well as HindIII and PvuII polymorphisms using PCR techniques. PCR products were characterized by PCR-RFLP and direct sequencing. Polymorphisms were examined for association with clinical features in UC patients. Genotype frequencies for LPL polymorphisms were also compared between UC patients and controls.

RESULTS: In patients with onset at age 20 years or younger, C/G and G/G genotypes for Ser447stop polymorphism were more prevalent than C/C genotype (OR = 3.13, 95% CI = 0.95-10.33). Patients with H^+/- or H^-/- genotype for HindIII polymorphism also were more numerous than those with H^+/+ genotype (OR = 2.51, 95% CI = 0.85-7.45). In the group with H^+/+ genotype for HindIII polymorphism, more patients had serum triglyceride concentrations over 150 mg/dL than patients with H^+/- or H^-/- genotype (P < 0.01, OR = 6.46, 95% CI = 1.39-30.12). Hypertriglycemia was also more prevalent in patients with P^+/+ genotypes for PvuII polymorphism (P < 0.05, OR = 3.0, 95% CI = 1.06-8.50). Genotype frequency for LPL polymorphism did not differ significantly between UC patients and controls.

CONCLUSION: Ser447stop and HindIII LPL polymorphisms may influence age of onset of UC, while HindIII and PvuII polymorphisms influence serum triglyceride in UC patients.

A polymorphism in lipoprotein lipase affects the severity of Alzheimer's disease pathophysiology

Emerging evidences indicate a role for lipoprotein lipase (LPL) in degenerative states. Genetic variations in the LPL gene were previously associated to lipid imbalance and coronary artery disease (CAD) risk and severity, a condition that shares pathological features with common Alzheimer's disease (AD). To evaluate whether these genetic variations associate with the risk and pathophysiology of common AD, autopsy-confirmed patients (242 controls, 153 AD) were genotyped for a PvuII single nucleotide polymorphism (SNP; rs285; referred to as the P+ allele) of LPL. Brain LPL mRNA levels, cholesterol levels, amyloid concentration, senile plaques and neurofibrillary tangles density counts were measured and contrasted with specific LPL genotypes. When adjusted for age and sex, homozygosity for the P+ allele resulted in an odds ratio of 2.3 for the risk of developing AD. More importantly, we report that the presence of the P+ allele of LPL significantly affects its mRNA expression level (n = 51; P = 0.026), brain tissue cholesterol levels (n = 55; P = 0.0013), neurofibrillary tangles (n = 52; P = 0.025) and senile plaque (n = 52; P = 0.022) densities. These results indicate that a common polymorphism in the lipoprotein lipase gene modulates the risk level for sporadic AD in the eastern Canadian population but more importantly, indirectly modulates the pathophysiology of the brain in autopsy-confirmed cases.

Association of HindIII and PvuII genetic polymorphisms of lipoprotein lipase with lipid metabolism and macrovascular events in type 2 diabetic patients

AIM

Lipoprotein lipase (LPL) is a key enzyme of lipid metabolism, and its genetic polymorphism may be a candidate for modulating lipid parameters in type 2 diabetic subjects (D2).

METHODS

In a group of 404 type 2 diabetic patients, aged 59.5+/-10.8y, BMI=28.9+/-5.3 kg/m2, HbA1c=8.2+/-1.9%, we studied the H and P polymorphisms at the LPL locus detectable with the restriction enzymes HindIII and PvuII. Patients were separated into 229 males (17H1H1, 84H1H2, 128H2H2 and 51P1P1, 110P1P2, 68P2P2) and 175 females (16H1H1, 69H1H2, 90H2H2 and 51P1P1, 85P1P2, 39P2P2), and compared on the basis of their lipid parameters and their macrovascular complications.

RESULTS

Triglyceride (TG) and HDL-cholesterol(c) concentrations differed between patients with and without coronary heart disease (CHD) (3.44+/-2.09 and 1.96+/-1.40 mmol/l for TGs and 1.05+/-0.24 and 1.34+/-0.40 mmol/l for HDL-c, P<0.001). HDL-c concentrations were lower in male H2H2 and P2P2 subjects (P<0.001), and TG levels were higher in male H2H2 and P2P2 subjects (P<0.0001 for Hind III and P<0.05 for PvuII). Allele frequency of the HindIII and PvuII restriction site was similar to those reported in other Caucasian populations and the presence of the H2/P2 variants was significantly higher in CHD patients. The prevalence of CHD in this population was 18% but was 29% in H2H2 and 38% in P2P2 subjects (P<0.02).

CONCLUSION

Thus, HindIII and PvuII polymorphisms seem to exert a modulating role on lipid profile particularly in male D2, contributing to increase the risk of macrovascular events.

The H+ allele of the lipoprotein lipase (LPL) HindIII intronic polymorphism and the risk for sporadic late-onset Alzheimer’s disease

A sample of 243 Italian patients affected by the sporadic late-onset form of Alzheimer's disease (AD) was studied for the HindIII intronic polymorphism of the lipoprotein lipase (LPL) gene and compared with a sample of 148 healthy subjects. Since this polymorphism has been reported to be associated with CAD and because the two pathologies share common aspects, we decided to study it in AD too. We found a difference in the allele distribution, in that the H+ allele was more frequent in patients (0.782) than in controls (0.720); this difference was not quite significant (P = 0.059). The odds ratio from the logistic regression analysis for the H+ carrying genotypes was 2.7 (95% CI = 1.01-7.21; P = 0.048). When the separate genotypes H+H+ and H+H- were entered into the analysis, only H+H+ was found to significantly increase the risk with respect to H-H- (P = 0.029). This means that carrying this allele significantly increases the risk of developing AD, and the risk is mostly associated with the H+H+ genotype.

Lipoprotein Lipase Gene Polymorphism and Lipid Profile in Coronary Artery Disease

Context.—Lipoprotein lipase (LPL) plays a central role in lipid metabolism, hydrolyzing triglyceride in chylomicrons and very-low-density lipoproteins. The PvuII polymorphic variant of LPL gene is common and might affect risk of coronary artery disease (CAD).

Objective.—Our aim was to determine whether LPL– PvuII polymorphism can be considered to be an independent risk factor or a predictor for CAD in Turkish subjects.

Design.—We used polymerase chain reaction and restriction enzyme digestion to determine the distribution of the previously described C→T transition that causes a PvuII polymorphism in intron 6 among healthy blood donors of Turkish origin and among angiographically confirmed CAD patients with comparable ethnic backgrounds.

Results.—For the PvuII genotypes, within the CAD group (n = 80), the +/− genotype was found in 39 individuals (48.8%), whereas 25 (31.3%) carried the +/+ genotype, and 14 (17.5%) carried the −/− genotype. Within the control group (n = 49), the −/− genotype was found in 19 individuals (38.8%), 16 (32.7%) carried the +/− genotype, and 14 (28.6%) carried the +/+ genotype. The genotype frequency distribution was significantly different (P = .049) in the CAD and control study groups. The most frequent genotype among CAD patients was +/−; this genotype was more frequent in patients than in control subjects. However, the −/− genotype was more prevalent in the control group. Lipoprotein lipase–PvuII polymorphism was found to be associated with fasting total cholesterol and low-density lipoprotein cholesterol levels. The +/+ genotype was found to have higher levels of total cholesterol and low-density lipoprotein cholesterol in both the CAD and control groups.

Conclusion.—There was a difference in the distribution of LPL–PvuII genotypes between the healthy subjects and the patients with CAD. Lipoprotein lipase–PvuII polymorphisms were not detected as independent risk factors for CAD in this study group, but had associations with lipid levels.

Selected genetic polymorphisms and plasma coagulation factor VII changes with exercise training

We assessed the effects of coagulation factor VII (FVII) gene polymorphisms, lipid-related polymorphisms, and exercise training-induced plasma lipoprotein lipid changes on FVII level changes with exercise training in middle- to older-aged men and women. Forty-six healthy sedentary men and women were stabilized on a low-fat diet and then underwent baseline testing, 6 mo of endurance exercise training, and final testing. Plasma FVII-Ag levels decreased with exercise training (106.7 ± 1.4 vs. 104.2 ± 1.6%, P = 0.005). There were no significant differences in FVII-Ag changes with exercise training between -323 (0/10 bp)/-401 (G/T) haplotype or -402 (G/A) genotype groups. FVII-Ag changes with training were not correlated with changes in plasma lipoprotein lipids. In linear regression analyses, FVII-Ag changes with training remained significant after adjusting for training-induced plasma lipoprotein lipid changes ( P = 0.01). FVII changes with training were associated with apolipoprotein E genotype ( P = 0.012); this relationship was still evident after adjusting for training-induced plasma lipoprotein lipid changes ( P = 0.047). FVII changes with training also were significantly associated with human ATPase binding cassette-1 genotype ( P = 0.018); this relationship persisted after accounting for the effect of the training-induced plasma lipoprotein lipid changes ( P = 0.045). We conclude that plasma FVII-Ag changes with exercise training are more closely related to selected lipid-related genotypes than FVII gene promoter variants.

Lipoprotein lipase is a gene for insulin resistance in Mexican Americans

The insulin resistance syndrome is increasingly recognized as a risk factor for cardiovascular disease. Lipoprotein lipase (LPL) is a candidate gene for components of the syndrome. A small number of studies have demonstrated association of single nucleotide polymorphisms within LPL and indirect or surrogate measures of insulin resistance, largely based on glucose and insulin values obtained in the fasting state or during an oral glucose tolerance test. To test directly whether LPL is an insulin resistance gene, we performed the hyperinsulinemic-euglycemic clamp in a large family-based population of Mexican Americans who were genotyped at six polymorphisms in LPL that define the most common haplotypes in the population. LPL haplotypes showed linkage to the glucose infusion rate (GINF), a direct physiologic measurement of insulin sensitivity (P = 0.034). In addition, significant associations with GINF were demonstrated for the most common haplotype (P = 0.031) and the fourth most common haplotype (P = 0.007). Haplotype 1 was associated with insulin sensitivity (mean GINF for haplotype 1 carriers = 383.0 mg/min) and haplotype 4 with insulin resistance (mean GINF for haplotype 4 carriers = 344.3 mg/min). This haplotype-based genetic analysis provides compelling evidence that variation in the LPL gene plays a role in determining insulin resistance in this ethnic group with a high prevalence of the insulin resistance syndrome.

Postprandial triglyceride levels in familial combined hyperlipidemia. The role of apolipoprotein E and lipoprotein lipase polymorphisms

The effect of apolipoprotein E genotype and polymorphisms of lipoprotein lipase gene on plasma postprandial triglyceride levels in familial combined hyperlipidemic subjects and their relatives have not been sufficiently studied. This study included sixteen familial combined hyperlipidemic parents (G1): age: 52 +/- 9 years with total-cholesterol: 7.2 +/- 1.7 mmol/L, fasting triglycerides: 2.8 +/- 1.4 mmol/L and sixteen children (G2) (twelve were normolipidemic): of age: 22 +/- 5 years with total-cholesterol: 5.2 +/- 1.1 mmol/L, fasting triglycerides: 2.06 +/- 1.8 mmol/L and twelve normolipidemic, healthy controls. Blood samples were taken fasting and 2, 4, 6, 8, 10 hr postprandially after the standard fat rich test meal. We determined lipid parameters, apolipoprotein E and lipoprotein lipase HindIII and PvuII polymorphisms as well. The 6-hr critical postprandial triglyceride values were abnormal in both G1: 5.88 +/- 2.7 mmol/L and G2: 3.53 +/- 2.7 mmol/L (p <0.001), respectively, and differed significantly (p <0.001) from each other. The subjects of familial combined hyperlipidemic families with E4 allele in both generations exhibited significantly (p <0.001) higher and extended postprandial lipemia. We did not find significant effects of lipoprotein lipase HindIII or PvuII polymorphisms on the fasting lipid values alone, however in normolipidemic subjects from the same families the homozygosity of HindIII variation was associated with higher triglyceride postprandial peak (p <0.01). The main findings of our study are that i.) normolipidemic G2 subjects in familial combined hyperlipidemic families have already abnormal postprandial status, and ii.) the 6 h postprandial triglyceride values were correlated with fasting triglyceride levels, which showed association with the apolipoprotein E4 allele.

Lack of association of lipoprotein lipase gene polymorphisms with coronary artery disease in the Saudi Arab population

CONTEXT

Previous studies reported an association of certain polymorphisms in the lipoprotein lipase (LPL) gene with the risk of coronary artery disease (CAD); however, these studies were small and inconsistent. In addition, none of these studies attempted to establish such an association in the Arab population.

OBJECTIVE

To determine whether 2 LPL polymorphisms (LPL-HindIII and LPL-PvuII located on introns 8 and 6, respectively, of the LPL gene) can be considered as independent risk factors or as predictors for CAD in Arabs.

DESIGN

We used polymerase chain reaction and restriction enzyme digestion to determine the distribution of the LPL-HindIII and LPL-PvuII polymorphisms among healthy blood donors of Arabic origin (BD group) and angiographically confirmed CAD patients (CAD group) with identical ethnic backgrounds.

RESULTS

For the HindIII genotypes, within the BD group (n = 410), the +/+ genotype was found in 206 individuals (50.2%), 173 (42.2%) carried the +/- genotype, and 31 (7.6%) carried the -/- genotype. Within the CAD group (n = 352), the +/+ genotype was found in 189 individuals (53.7%), 138 (39.2%) carried the +/- genotype, and 25 (7.1%) carried the -/- genotype. P values of.38,.45, and.92 were obtained for the +/+, +/-, and -/- genotypes, respectively. For the PvuII genotypes, within the BD group (n = 511), the +/+ genotype was found in 182 individuals (35.6%), 248 (48.5%) carried the +/- genotype, and 81 (15.9%) carried the -/- genotype. Within the CAD group (n = 431), the +/+ genotype was found in 138 individuals (32%), 225 (52.2%) carried the +/- genotype, and 68 (15.8%) carried the -/- genotype. P values of.28,.29, and.98 were obtained for the +/+, +/-, and -/- genotypes, respectively. The distribution and the allele frequency of these 2 LPL variants were similar in CAD and BD study groups and followed the Hardy-Weinberg equilibrium.

CONCLUSION

There was no difference in the distribution of both LPL polymorphisms between the healthy group and the CAD group. Therefore, these 2 LPL polymorphisms cannot be considered as independent risk factors or as predictors for CAD in this population.

The lipoprotein lipase gene HindIII polymorphism is associated with lipid levels in early-onset type 2 diabetic patients

Lipoprotein lipase (LPL) plays a central role in triglyceride metabolism, and the LPL gene T495G HindIII polymorphism has been associated with variations in lipid levels and heart disease in Caucasians with the more common H+ allele being associated with adverse lipid profiles and increased risk of CHD. We investigated this polymorphism in 785 Chinese subjects with varying components of the metabolic syndrome, including 61.4% with early-onset type 2 diabetes (age at diagnosis < or = 40 years), and 167 healthy control subjects using a polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) method. The allele and genotype frequencies were similar in the patients and control subjects. When grouped above or below standard cutoffs for triglyceride levels, the H+ allele was more frequent in hypertriglyceridemic than that in normotriglyceridemic subjects in the total population (81.5% v 76.1%) and early-onset type 2 diabetics (84.4% v 77.4%, both P <.05). Moreover, H+H+ carriers had significantly higher plasma triglyceride and lower high-density lipoprotein (HDL)-cholesterol levels when compared to subjects with the H- allele in the total population, and in patients with early-onset diabetics (both P <.05). In the total population and the early-onset diabetic patients, this relationship was confined to males when gender was considered. We conclude that the H+ allele of the LPL gene HindIII polymorphism is associated with higher plasma triglyceride and lower HDL-cholesterol levels in Chinese patients with early-onset diabetes.

Nephropathy in type 1 diabetes: a manifestation of insulin resistance and multiple genetic susceptibilities? Further evidence from the Pittsburgh Epidemiology of Diabetes Complication Study

BACKGROUND

The pathogenesis of diabetic nephropathy remains unclear, although previous reports implicate a wide range of putative genetic and metabolic factors.

METHODS

Incident and prevalent cases of overt nephropathy (ON), defined as an albumin excretion rate>200 microg/min in at least two of the three timed urines, from the Pittsburgh Epidemiology of Diabetes Complication Study (a prospective epidemiologic study of an incident cohort of childhood onset type 1 diabetic subjects) were studied.

RESULTS

Incidence analyses reveal differences in univariate baseline risk factors that predict ON within 5 years of measurement [low-density lipoprotein (LDL) cholesterol, triglycerides, white blood cell count, and hypertension] and those that predict in the long-term, that is, 6 to 10 years after baseline, hemoglobin A1 (Hb A1). Estimated glucose disposal rate (calculated using a formula derived from euglycemic-hyperinsulinemic clamp studies), however, strongly (P < 0.001) predicted ON throughout follow-up. Comparing individuals who were most susceptible to ON (those with an onset before 20 years duration of type 1 diabetes and before the development of other advanced complications) with the least susceptible (late or no occurrence of ON despite the development of other advanced complications) revealed otherwise undetected genetic associations [that is, apolipoprotein E (Apo E), angtiotensin-converting enzyme insertion/deletion (ACE I/D), and lipoprotein lipase (LPL) HindIII polymorphism) with odds ratios ranging from 2.9 to 7.1.

CONCLUSIONS

In type 1 diabetes insulin resistance is an underlying risk state for ON, which may be accelerated by other disturbances (for example, hypertension and dyslipidemia). A novel approach to classifying (that is, phenotyping) subjects, which compares those at the extremes of susceptibility, reveals strong genetic associations and important interactions with other risk factors not otherwise apparent.

Lipoprotein lipase and APOE/APOC-I/APOC-II gene cluster diversity in native Brazilian populations

Allele and haplotype frequencies for the T-93G, Hind III, and Pvu II variants of the lipoprotein lipase gene (LPL), and Hpa I and Ava II restriction site polymorphisms (RSP) of the APOE/C-I/C-II gene cluster were determined in 143 individuals from five Brazilian Indian tribes. These results were integrated with those previously reported for APOE. Marked interethnic variability occurs in these sites. A strong linkage disequilibrium was observed between the APOE and APOC-I loci (D' = 0.81; P < 0.00001). Linkage disequilibrium between the Hind III and Pvu II RSPs of the LPL gene was also observed (D' = 1; P < 0.001), but none of these RSPs were in linkage disequilibrium with the T-93G mutation. Considering both loci, heterozygosity was estimated as 0.45, but it was lower in the Xavante and Surui populations, in accordance with the historical and biodemographical data of these Amerindians. The results reported here may have implications for understanding interpopulation differences in lipid levels and coronary heart disease prevalences.

Lipoprotein lipase polymorphisms and responses to long-term overfeeding

OBJECTIVES

The role of the lipoprotein lipase (LPL) gene Hind III, S447X, Bam HI and Pvu II polymorphisms on body composition and lipid and lipoprotein changes in response to long-term overfeeding was studied.

SUBJECTS

Twelve pairs of male monozygotic twins ate a 4.2 MJ day-1 energy surplus, 6 days a week, during a period of 100 days.

RESULTS

Overfeeding induced a decrease in high-density lipoprotein 2 cholesterol (HDL2-C) and HDL2-C to HDL3-C ratio in the H2H2 (n = 12) subjects of the LPL Hind III polymorphism. In contrast, the H1H1/H1H2 (n = 12) subjects experienced increases both in the HDL2-C and HDL2-C to HDL3-C ratio (P = 0.009 and 0.007, respectively, for differences in percentage changes between H2H2 and H1H1/H1H2). In addition, the H2H2 genotype was associated with higher levels of very-low-density lipoprotein triglyceride (VLDL-TG) (P < 0.03) and VLDL-C (P < 0.05) before and after overfeeding and higher HDL-TG levels (P < 0.003) after overfeeding. Postheparin lipoprotein lipase (PH-LPL) activity tended to increase in H1H1/H1H2 and decrease in H2H2 subjects. The H2H2 subjects had lower total HDL-C than those with the genotype H1H1/H1H2 4 months and 5 years after overfeeding (P = 0.04 and 0.10, respectively). The plasma lipid differences were similar amongst subjects with the S447S (n = 4) genotype of the S447X and H2H2 genotype of the Hind III polymorphisms. Body composition changes in response to overfeeding were not different between the Hind III genotypes. LPL Pvu II and Hind III polymorphisms were associated weakly with body weight gain (P = 0.015-0.039) but strongly with adipose tissue LPL activity (P < 0.01) after the caloric surplus.

CONCLUSIONS

We conclude that the H2H2 subjects of the LPL gene Hind III polymorphism experience a decrease in the concentration of antiaterogenic lipoproteins when they are exposed to long-term positive energy balance. This may have been partly caused by a diminished catabolism of TG-rich particles in H2H2 subjects. LPL Pvu II and Bam HI polymorphisms were associated with body weight gain and adipose tissue LPL activity. Genetic variation at the LPL locus could thus be one of the factors responsible for the inter-individual differences observed in plasma lipid and lipoprotein responses to chronic positive energy balance. It must be kept in mind that the sample size for this study was small. Nonetheless, it provides useful information on the genes and pathways that should be further explored.

Gender specific associations of the Trp64Arg mutation in the beta3-adrenergic receptor gene with obesity-related phenotypes in a Mediterranean population: interaction with a common lipoprotein lipase gene variation

OBJECTIVE

To investigate the association between the Trp64Arg beta3-adrenergic receptor (ADRB3) mutation and obesity-related phenotypes in a Mediterranean Spanish population considering the effect of other genetic and environmental factors. DESIGN AND SUBJECT: Cross-sectional study in 1063 (476 men and 587 women) randomly selected from this population (aged: 18-68 years).

MEASUREMENTS

Anthropometric (weight, height and waist-to-hip ratio), blood pressure, biochemical (lipids, fasting glucose, and uric acid), life-style variables, and the Trp64Arg, HindIII-Lipoprotein lipase (LPL) and apolipoprotein E polymorphism.

RESULTS

Frequency of the Arg64 allele was low (0.051; 95% CI: 0.042-0.060). We found gender-specific associations between the Trp64Arg mutation and obesity related phenotypes. In men, carriers of the Arg64 variant had higher body mass index (BMI) (27.63 +/- 3.81 vs. 26.34 +/- 3.57 kg m-2, P=0.049) and total cholesterol (5.85 +/- 1.45 vs. 5.28 +/- 1.06 mmol L-1; P=0.011) compared with wild-type individuals. Logistic regression analysis, revealed that the risk of overweight was two times higher in male carriers of the Arg64 allele. In women, the Arg64 variant was only associated with higher fasting glucose (P=0.031). These genotype effects persisted after adjustment for age, genetic and life-style variables. For the LPL polymorphism, the H-/H- genotype was associated with lower BMI and with lower risk of overweight (OR: 0.49; 95% CI: 0.30-0.81) in both men and women. However, after adjustment for covariates, these associations only remained statistically significant (P < 0.02) in women. Moreover, in women, a statistically significant interaction (P=0.026) between the LPL and the ADRB3 gene loci in determining BMI was found. Thus, the Arg64 allele was associated with a higher BMI only in H+/H+ women.

CONCLUSIONS

The Trp64Arg mutation was associated with BMI and lipids in men. In women, an additional gene-gene interaction with the LPL-HindIII polymorphism may explain the results.

Genetic variation at the lipoprotein lipase locus and plasma lipoprotein and insulin levels in the Québec Family Study

The associations between the S447X, BamHI, HindIII and PvuII DNA variants of the lipoprotein lipase (LPL) gene and indicators of body fat, fat distribution and plasma lipids and insulin were studied in the Québec Family Study cohort. Strong linkage disequilibrium among all the markers was observed. For the S447X polymorphism, plasma very low density lipoprotein (VLDL)-cholesterol (chol) (P<0.001), total triglyceride (TG) (P=0.033) and VLDL-TG (P<0.001) levels were lower and high density lipoprotein (HDL)-chol level higher (P<0.001) in the subjects homozygous or heterozygous for X447 (X447+, n=160) compared to the homozygotes for the S447 allele (X447-, n=576). The BamHI, PvuII and HindIII polymorphisms were not associated with the plasma lipid values when all X447 allele carriers were removed. In addition, the HindIII polymorphism as well as the HindIII and S447X markers combination influenced the insulin area under the curve during an oral glucose tolerance test. We conclude that DNA sequence variation in the LPL gene contributes significantly to the variability in the levels of VLDL-chol, total- and VLDL-TG as well as HDL-chol. The effects of the other polymorphisms considered here are most likely mediated by their linkage disequilibrium with the S447X mutation. In addition, genetic variation at the LPL locus may, by an unknown mechanism, influence insulin metabolism but not body fat variability.

A single Ser259Arg mutation in the gene for lipoprotein lipase causes chylomicronemia in Moroccans of Berber ancestry

Lipoprotein lipase (LPL) is the rate-limiting enzyme for the hydrolysis of triglyceride-rich lipoproteins. Numerous LPL gene mutations have been described as a cause of familial chylomicronemia in various populations. In general, allelic heterogeneity is observed in LPL deficiency in different populations. However, a founder effect has been reported in certain populations, such as French Canadians. Although familial chylomicronemia is observed in Morocco, the molecular basis for the disease remains unknown. Here, we report two unrelated Moroccan families of Berber ancestry, ascertained independently in Holland and France. In both probands, familial chylomicronemia manifested in infancy and was complicated with acute pancreatitis at age 2 years. Both probands were homozygous for a Ser259Arg mutation, which results in the absence of LPL catalytic activity both in vivo and in vitro. In heterozygous relatives, a partial decrease in plasma LPL activity was observed, sometimes associated with combined hyperlipidemia. This mutation previously unreported in other populations segregated on an identical haplotype, rarely observed in Caucasians, in both families. Therefore, LPL deficiency is a cause of familial chylomicronemia in Morocco and may result from a founder effect in patients of Berber ancestry.

Frequency and allelic association of common variants in the lipoprotein lipase gene in different ethnic groups: the Wandsworth Heart and Stroke Study

The lower serum triglyceride (Tg), higher high density cholesterol (HDL-C) levels and low coronary heart disease (CHD) mortality in black populations, contrast with that in whites. By comparison, South Asian populations display a higher mortality from CHD associated with increased Tg and low HDL-C levels. Lipoprotein lipase (LPL) plays a major role in Tg metabolism. To determine if variation in the LPL gene contributes to the differences in lipid levels, we studied the frequencies and allelic associations of five common variants in the lipoprotein lipase (LPL) gene (-93T/G, D9N, N291S, S447X, and the HinddIII RFLP in intron 8) with serum Tg and HDL-cholesterol concentrations in population samples of middle-aged men and women of whites, South Asians, and blacks of African origin co-resident in South London. Significantly higher frequencies of the H(-) (P < 0.00001), N9 (P < 0.001), and -93G (P < 10(-10)) alleles were seen in blacks compared to the other two groups. Allelic association between -93G and N9, and H(+) and X447 was strong in all three groups. However, no association was observed between serum Tg and HDL-cholesterol concentrations and these variants in the three ethnic groups. A single common polymorphism in the LPL gene is unlikely to account for the differences in fasting serum Tg in populations of different ethnic background. The importance of the differences in frequencies and the mechanism(s) whereby these may contribute towards a beneficial LPL genotype in black populations remain to be determined.

Association of sets of alleles of genes encoding beta3-adrenoreceptor, uncoupling protein 1 and lipoprotein lipase with increased risk of metabolic complications in obesity

OBJECTIVE

To investigate the relationship between the polymorphisms of the beta3-AR (Trp64Arg), UCP1 (A-->G) and LPL (HindIII and PvuII) loci and the metabolic complications associated with obesity in a Turkish population.

SUBJECTS

271 unrelated individuals of Turkish origin including obese (body mass index, BMI>30 kg¿m2) and lean (BMI< or =25 kg¿m2) subjects.

MEASUREMENTS

Anthropometric (weight, height and blood pressure) and metabolic measurements (plasma levels of glucose, cholesterol and triglycerides), and determination of beta3-AR, UCP1 and LPL genotypes by polymerase chain reaction followed by enzymatic digestion.

RESULTS

The distributions of genotypes for each candidate gene (beta3-AR, UCP1 and LPL) were similar between the obese and the lean subjects. The Arg64 allele of the beta3-AR gene was absent from massively obese men. GG carriers of the A-->G variant of the UCP1 gene showed BMI-associated increases of cholesterol levels which were more marked than both AA (P=0.027) and AG (P=0.039) carriers. Obese P+ carriers of the LPL PvuII variant had significantly higher levels of glucose than non-carriers (P=0.011), whereas obese P+P+ carriers did not have significantly different levels of triglycerides than non-carriers (P=0.087). Moreover, carriers of both alleles (G&P+) had higher levels of glucose than non-carriers (P=0.048), but did not have significantly different levels of triglycerides than non-carriers (P=0.125). However, the BMI-associated increase of triglycerides of P+&G carriers was significantly more marked than that of P+ carriers (P=0.0085).

CONCLUSION

Our data support the idea that alleles of specific genes (UCP1, LPL and beta3-AR) might play a role in the development of certain metabolic complications of obesity and might have additive effects when combined with each other (as in the case of UCP1 and LPL). International Journal of Obesity (2000)24, 93-100

Human lipoprotein lipase HindIII polymorphism in young patients with myocardial infarction

We investigated the possibility that the DNA HindIII polymorphism of human lipoprotein lipase (LPL) is associated with the severity of coronary artery disease (CAD) determined by angiography in young patients who survived a myocardial infarction (MI). Conflicting studies have explored the relationship linking CAD severity to the HindIII restriction site polymorphism at the LPL gene locus, and to our knowledge, no data are available from Italy. The patients were aged less than 45 years (mean age, 40.1 +/- 3.9 years); 83 were male and four were female. The 87 case-patients had a Q-wave or non-Q-wave infarction (67.3% and 32.7%, respectively); the MI was anterior (50.5%), lateral (41.7%), or inferior (7.8%). Analysis of coronary angiograms showed the absence of critical stenosis in 13.8% and the presence of monovessel disease in 50.6% and multivessel disease in 35.6% of the case-patients. The allelic frequency of the HindIII H(-) and H(+) allele was 0.37 and 0.63, respectively. There was a striking association between the HindIII polymorphism and the number of diseased vessels. The patients with HindIII(+/+) genotypes were significantly more likely to have double- or triple-vessel disease and less likely to have no significantly diseased vessels. In this study, we demonstrated that the homozygous form of the LPL HindIII(+) allele increases the risk of multivessel disease by a factor of 4 in an Italian group of young MI survivors. This association was independent from the smoking status and a positive family history for CAD and hypertension, which are known to predict CAD severity. The discrepancies in the results of these studies are difficult to explain. The lack of homogeneity in the study populations (age at which CAD occurred, number of enrolled patients, and geographical origin) and differences in the assessment of CAD severity may account for these conflicting results.

Exercise training-induced blood pressure and plasma lipid improvements in hypertensives may be genotype dependent

Exercise training improves cardiovascular disease risk, but individual responses are highly variable. We hypothesized that common polymorphic gene variations would affect these responses. Sedentary obese hypertensive older men who had undergone exercise training were typed at the apolipoprotein (apo) E, angiotensin-converting enzyme (ACE), and lipoprotein lipase (LPL) loci. Individuals of all genotype subgroups were generally similar before training; they also changed body weight, body composition, and &f1;O(2)max similarly with training. ACE insertion/insertion (II) and insertion/deletion (ID) genotype individuals (n=10) tended to reduce systolic blood pressure more with training than deletion/deletion (DD) individuals (n=8) (-10 versus -5 mm Hg, P=0. 16). ACE II and ID individuals decreased diastolic blood pressure more with training than DD individuals (-10 versus -1 mm Hg, P<0. 005). Systolic blood pressure reductions with training were also larger in apoE3 and E4 (n=15) than apoE2 men (n=3) (-10 versus 0 mm Hg, P<0.05). The same trend was evident for diastolic blood pressure (-7 versus -3 mm Hg), but the difference was not significant. Systolic (14 versus -6 mm Hg, P=0.08) and diastolic (-9 versus -5 mm Hg, P=0.10) blood pressure reductions tended to be greater in LPL PvuII +/+ (n=4) than +/- and -/- individuals (n=14). Systolic (-10 versus 3 mm Hg, P<0.05) and diastolic (-9 versus 2 mm Hg, P<0.05) blood pressure reductions were larger in LPL HindIII +/+ and +/- (n=15) than -/- persons (n=3), respectively. LPL PvuII -/- individuals (n=3) had larger increases in HDL cholesterol (11 versus 2 mg/dL, P<0.05) and HDL(2) cholesterol (8 versus 0 mg/dL, P<0.05) than LPL PvuII +/- and +/+ individuals (n=15). These results are consistent with the possibility that apoE, ACE, and LPL genotypes may identify hypertensives who will improve blood pressure, lipoprotein lipids, and cardiovascular disease risk the most with exercise training.

The Lipoprotein Lipase HindIII Polymorphism: Association with Total Cholesterol and LDL-Cholesterol, but not with HDL and Triglycerides in 342 Females

Background: Lipoprotein lipase (LPL) is the rate-limiting enzyme in the hydrolysis of core triglycerides in chylomicrons and VLDL.

Methods: We investigated the association between the HindIII polymorphism of the LPL gene and fasting glucose, lipid, and lipoprotein concentrations in 683 Caucasians. We first stabilized the study subjects, using an 8-day diet and exercise intervention program before obtaining blood samples. The use of this standardization period reduced the variance of all glucose and lipid concentrations.

Results: In our study, the HindIII allele frequencies for females and males were 0.29 and 0.34 for H− and 0.71 and 0.66 for H+, respectively. We found in females, but not in males, a significant association between the HindIII genotype and total cholesterol (P = 0.007) and LDL-cholesterol (P = 0.018), with females homozygous for the rare H− allele having the lowest, heterozygotes (H−/+) having intermediate, and women homozygous for the common H+ allele having the highest of each of these lipid traits. With regard to triglycerides, HDL-cholesterol, and glucose, no significant effect of the HindIII genotype was noted in either gender.

Conclusions: These results suggest that in a gender-specific manner, the rare LPLHindIII H− allele has a cholesterol-lowering and, therefore, potentially cardioprotective effect compared with the common H+ allele.

Lipoprotein lipase gene mutations, plasma lipid levels, progression/regression of coronary atherosclerosis, response to therapy, and future clinical events. Lipoproteins and Coronary Atherosclerosis Study

Mutations in human lipoprotein lipase (LPL) gene are potential risk factors for susceptibility to coronary artery disease (CAD). The objectives of this study were to determine the influence LPL mutations Asn291Ser and Ser447Ter on plasma lipid levels, regression and progression of CAD, clinical events rate, and response to fluvastatin therapy in the Lipoprotein and Coronary Atherosclerosis Study (LCAS) population. LCAS is a double blind, randomized, placebo-controlled study designed to test the influence of fluvastatin on progression or regression of CAD. The Asn291Ser and Ser447Ter genotypes were determined by polymerase chain reaction (PCR) and restriction enzyme digestion. Fasting plasma lipid profiles were measured and quantitative coronary angiography was performed at baseline and 2.5 years following randomization. Fatal and non-fatal cardiovascular events during the follow-up period were recorded. A total of 4% (14/363) and 18% (62/352) of the subjects had the Asn291Ser and Ser447Ter mutations, respectively. Overall, there was no statistically association between the Asn291Ser and Ser447Ter mutations and the baseline or final mean plasma levels of lipids, number of coronary lesions, total occlusions, the mean minimal lumen diameter (MLD) stenoses and the clinical events rate. However, patients with the Ser447Ter variant had a slightly higher baseline high density lipoprotein-cholesterol (HDL-C) level (46.2 +/- 12 vs 43.2 +/- 11, P = 0.057), less increase in plasma HDL levels in response to fluvastatin therapy (3 vs 11%, P = 0.056) and a higher cardiovascular events rate (23 vs 13%, P = 0.056). Thus, the Ser447Ter variant had a modest influence on plasma HDL levels and the rate of cardiovascular events. These changes were of borderline statistical significance. Neither the Ser447Ter nor the Asn291Ser mutation had a major impact on susceptibility to CAD, progression or regression of CAD, clinical events rate or response to fluvastatin therapy in LCAS population.

Association of lipoprotein lipase gene polymorphisms with coronary artery disease

OBJECTIVES

The purpose of this study was to test whether the HindIII (+) and PvuII (-) or (+) restriction enzyme-defined alleles are associated with angiographic coronary artery disease (CAD).

BACKGROUND

Lipoprotein lipase (LPL) plays a central role in lipid metabolism, hydrolyzing triglyceride in chylomicrons and very low density lipoproteins. Polymorphic variants of the LPL gene are common and might affect risk of CAD.

METHODS

Blood was drawn from 725 patients undergoing coronary angiography. Leukocyte deoxyribonucleic acid segments containing the genomic sites were amplified by the polymerase chain reaction and digested, and polymorphisms were identified after electrophoresis in 1.5% agarose gel.

RESULTS

In no-CAD control subjects (n = 168), HindIII (-) and (+) allelic frequencies were 28.6% and 71.4%, and (-) and (+) alleles were carried by 44.0% and 86.9% of subjects, respectively. Control PvuII (-) and (+) allelic frequencies were 41.7% and 58.3%, and (-) and (+) alleles were carried by 64.3% and 81.0%, respectively. In CAD patients (>60% stenosis; n = 483), HindIII (+) allelic carriage was increased (93.8% of patients, odds ratio [OR] = 2.28, confidence interval [CI] 1.27 to 4.00). Also, PvuII (-) allelic carriage tended to be more frequent in CAD patients (OR = 1.33, CI 0.92 to 1.93). Adjusted for six CAD risk factors and the other polymorphism, HindIII (+) carriage was associated with an OR = 2.86, CI 1.50 to 5.42, p = 0.0014, and PvulI (-) carriage, OR = 1.42, CI 0.95 to 2.12, p = 0.09. The two polymorphisms were in strong linkage disequilibrium, and a haplotype association was suggested.

CONCLUSIONS

The common LPL polymorphic allele, HindIII (+), is moderately associated with CAD, and the PvuII (-) allele is modestly associated (trend). Genetic variants of LPL deserve further evaluation as risk factors for CAD.

The Gln-Arg 191 polymorphism of the human paraoxonase gene is not associated with the risk of coronary artery disease among Chinese in Taiwan

Paraoxonase (PON1) is a high density lipoprotein-associated enzyme capable of hydrolyzing lipid peroxides, and thus, might protect lipoproteins from oxidation. A common polymorphism due to an amino acid substitution (Gln-Arg) at codon 191 is considered to be a major determinant of variation in serum PON1 activity. Recent studies have suggested that the PON1-191 polymorphism is an independent risk factor for coronary atherosclerosis in patients with or without diabetes mellitus. The association of PON1-191 polymorphism genotypes and coronary artery disease (CAD) among Chinese subjects in Taiwan was examined. The genotype of 218 angiographically documented CAD patients and the same number of age- and sex-matched control subjects was determined. Genotypes AA, AB and BB were present in 25 (11%), 102 (47%) and 91 (42%) of control subjects, respectively, and in 30 (14%), 96 (44%) and 92 (42%) of CAD patients, respectively (chi2 = 0.57, P = 0.75 between groups). The frequency of the A allele was 0.36 for the control group and 0.35 for CAD patients (P = 0.94). No significant differences in the PON1-191 genotype frequencies could be found between groups when multivariate logistic regression analysis was performed, or different subgroups of age, sex or risk factors were analyzed. Among control subjects, there was also no significant difference between genotypes of the PON1-191 polymorphism and various clinical and lipid variables. In conclusion, our data suggest that there is no association between the Gln-Arg 191 polymorphism of the human PON1 gene and CAD among Chinese subjects in Taiwan.

Lipoprotein lipase gene variation is associated with a paternal history of premature coronary artery disease and fasting and postprandial plasma triglycerides: the European Atherosclerosis Research Study (EARS)

The H-allele of the intron 8 HindIII polymorphism in the lipoprotein lipase (LPL) gene has been associated with a lower risk of myocardial infarction (MI) and plasma levels of triglycerides (TG). To test whether the HindIII site was in linkage disequilibrium with the functional variant LPL Serine447Stop (S447X), subjects from the European Atherosclerosis Research Study (EARS I) were genotyped for both polymorphic sites. This study included 515 offspring of fathers with a premature (<55 years old) MI, who were designated cases, and 930 age- and sex-matched control subjects from five different regions of Europe. Linkage disequilibrium between the two sites was very strong (>.99), with only three of the four possible haplotypes identified: H+S447, H-S447, and H-X447. The frequency of the H-X447 but not of the H-S447 haplotype was significantly lower in cases than in control subjects (.090 versus .117, P<.01) suggesting a protective effect for MI, with this difference being consistent in all five regions of Europe. Compared with individuals homozygous for the H+S447 haplotype, the odds ratio of having a paternal history of premature MI for H-X447 heterozygotes (approximately 20% of the population) was 0.71 (95% confidence interval, 0.55 to 0.92). In addition, there was an increase of the H-X447 haplotype frequency from north to south in control subjects (0.119 in Finland to 0.143 in the Mediterranean region, P<.01). Compared with the H+S447 haplotype, the H-X447 haplotype was associated with significantly lower concentrations of plasma TGs (5.4% lower, P=.01), with this effect being consistent over the regions of Europe. There was no significant evidence for a heterogeneity of effect between males and females or between cases and control subjects, although the effect on TG levels appeared to be the greatest in male cases (11% lower, P=.05). In a second study (EARS II), of 332 cases and 342 control subjects, postprandial clearance of TGs after a standard fat meal was examined. The H-X447 haplotype was associated with significantly lower postprandial triglyceride levels than was the H+S447 haplotype (9.4% smaller area under the curve, P<.05). Thus, the effects on MI risk and plasma lipids associated with the H allele appeared to be mainly mediated by the X447 mutation, and although the lowering effects associated with the H-X447 haplotype on fasting and postprandial TGs are not large, they are consistent with the lowering effect observed on MI risk throughout Europe.

Influence of PvuII (intron 6) polymorphism of the lipoprotein lipase gene on cord plasma lipid and apolipoprotein levels in Indian and Chinese newborns of Singapore

The influence of the PvuII polymorphism (intron 6) of the lipoprotein lipase (LPL) gene on cord plasma lipid traits was studied in 252 ethnic Chinese and 240 ethnic Indian newborns of Singapore. The allelic frequencies of P+ (presence of the restriction site) were 0.67 and 0.56 in the Chinese and Indian newborns, respectively, similar to their respective adult populations. The genotype distributions at the PvuII site were at Hardy Weinberg equilibrium in both ethnic Chinese (chi2 = 2.0) and ethnic Indians (chi2 = 3.6). Cord blood HDL-cholesterol (HDL-C) levels are higher in newborn Chinese than newborn Indians. In addition, cord blood LDL-cholesterol (LDL-C), apoB, and lipoprotein(a) levels are lower in newborn Chinese than newborn Indians. Both newborn Chinese and Indian male homozygotes for P- allele have higher cord blood LDL-C levels than newborns with the more common P+P+ or P-P+ genotypes. In Chinese male newborns, the LDL-C levels were 0.76 +/- 0.61 mmol/L, 0.53 +/- 0.29 mmol/L and 0.46 +/- 0.25 mmol/L, respectively (p = 0.01). In Indian male newborns, the LDL-C levels were 0.88 +/- 0.35 mmol/L for the P-P- genotype and 0.65 +/- 0.24 mmol/L for the P+P+ genotype (p = 0.003). In addition, the influence of the P- allele on LDL-C levels is remarkably similar in both ethnic groups, accounting for 8.48% of the population variance in the Chinese newborns and 8.09% in the Indian newborns. In contrast, no obvious effect of genotype is seen in this lipid parameter in the newborn females of either ethnic groups. There is presence of significant genotype specific influence on the LDL-C levels in cord plasma in male newborns, suggesting an early expression of the LPL gene locus.

Common variation in the lipoprotein lipase gene: effects on plasma lipids and risk of atherosclerosis

The importance of the enzyme lipoprotein lipase (LPL) in the development of dyslipidaemia and atherosclerosis is increasingly recognised. Variations in the LPL gene which are common in the general population have been shown to be associated with alterations in plasma lipids. D9N and N291S both occur at carrier frequencies of up to about 5% and have been associated with increased plasma triacylglycerol and decreased high density lipoprotein cholesterol concentrations, effects which seem to be magnified in more obese individuals. S447X carrier frequency is approximately 20%, but unlike carriers of N9 or S291, X447 carriers appear to have a more favourable lipid profile. A transition within the LPL promoter at position-93 may lead to increased LPL activity and have a beneficial effect on plasma lipids. Greater knowledge of the underlying mechanisms of these variations within the LPL gene may be of considerable importance in understanding genetic predisposition to atherosclerosis and heart disease.

Recessive inheritance of obesity in familial non-insulin-dependent diabetes mellitus, and lack of linkage to nine candidate genes

Segregation analysis of body-mass index (BMI) supported recessive inheritance of obesity, in pedigrees ascertained through siblings with non-insulin dependent diabetes mellitus (NIDDM). BMI was estimated as 39 kg/m2 for those subjects homozygous at the inferred locus. Two-locus segregation analysis provided weak support for a second recessive locus, with BMI estimated as 32 kg/m2 for homozygotes. NIDDM prevalence was increased among those subjects presumed to be homozygous at either locus. Using both parametric and nonparametric methods, we found no evidence of linkage of obesity to any of nine candidate genes/regions, including the Prader-Willi chromosomal region (PWS), the human homologue of the mouse agouti gene (ASP), and the genes for leptin (OB), the leptin receptor (OBR/DB), the beta3-adrenergic receptor (ADRB3), lipoprotein lipase (LPL), hepatic lipase (LIPC), glycogen synthase (GYS), and tumor necrosis factor alpha (TNFA).